A category of data. The broadest data types are alphanumeric and numeric. Programming languages allow for the creation of several data types, such as integer (whole numbers), floating point, binary numbers, date, string (text) and logical (true/false).
When data are assigned a type in a programming language, they cannot be treated like another type under normal circumstances. For example, alphanumeric data cannot be added and subtracted, and individual digits within a numeric value cannot be compared or computed. Date types can only contain valid calendar days, months and years. See
type system,
variable typing and
casting.